Sparkling beverage container with improved bubbling behavior

ABSTRACT

Carbonated beverage container 1, in particular a glass, comprising a sealed wall made of at least one structural material, the sealed wall defining an internal surface having a bottom portion between a bottom 4 of the sealed wall and a region of maximum diameter and an edge portion located above the bottom portion, the sealed wall comprising, in the bottom portion, a plurality of open pores 6 forming a pattern occupying an area of between 0.01 and 5%, preferably between 0.10 and 1%, of the area of the bottom portion and having an open cross shape.

FIELD OF THE INVENTION

The invention relates to the field of containers for liquids, and more particularly glassware articles.

BACKGROUND

During the manufacture of beverage containers such as glass goblets, the surfaces created are generally made as smooth as possible, in particular to give them good transparency and for aesthetic reasons.

The serving of a sparkling beverage in a container generates effervescent phenomena, or bubbling, and the accumulation of form on the surface. For the serving of beer or sparkling wine, for example, it is desirable to generate and maintain effervescence. The regions of bubble genesis in a glass are called nucleation sites.

It has been found that the presence of irregularities in the surfaces of the container in contact with sparkling beverage favors the appearance of bubbles from the gas dissolved in said sparkling beverage. To promote bubbling, internal surfaces with a rough relief have therefore been created in containers. When filling the container with a carbonated liquid such as a sparkling beverage, crevices in the internal surface trap pockets of air. The interfaces between the liquid and the air pockets allow better gas exchange. The crevices then form nucleation regions.

EP 0 703 743 describes a method for adding material to a surface to create nucleation sites and improve bubbling. A browning of the bottom of the glass has sometimes been observed. FR 2 531 891 describes a method for the ablation of material favoring the appearance of a region of gas evolution. Application examples are given in WO 2010/048488.

Patent FR 3 008 295 proposes creating nucleation sites inside a beverage container by surface irregularities on the bottom of the container on which a hydrophobic layer is then deposited. FR 3 065 360 proposes depositing a hydrophobic layer on the bottom of a beverage container and then providing continuity solutions therein by laser shots.

FR 3 081 304 describes a container whose bottom is provided with a layer of enamel, grains of enamel on the surface of and fixed to the layer of enamel, and a hydrophobic compound on a portion of the surface of the enamel grains. Application FR n° 1859699 will be published after the date of filing of this document. The Applicant has identified the need to improve the quality of bubbling.

Pr. Liger-Belair and his team from UMR CNRS 7331—University of Reims Champagne-Ardenne have published on effervescence:

Liger-Belair, G. “The physics behind the fizz in champagne and sparkling wines” European Physical Journal: Special Topics 201, 1-88, 2012.

Liger-Belair, G. “La physique des bulles de champagne” Annales de Physique (Paris) 27 (4), 1-106, 2002.

Liger-Belair, G.; Conreux, A.; Villaume, S.; Cilindre, C. “Monitoring the losses of dissolved carbon dioxide from laser-etched champagne glasses” Food Research International, 54, 516-522, 2013.

Liger-Belair, G.; Voisin, C.; Jeandet, P. “Modeling non-classical heterogeneous bubble nucleation from cellulose fibers: Application to bubbling in carbonated beverages” Journal of Physical Chemistry B 109, 14573-14580, 2005.

Liger-Belair, G.; Parmentier, M.; Jeandet, P. “Modeling the kinetics of bubble nucleation in champagne and carbonated beverages” Journal of Physical Chemistry B110, 21145-21151, 2006.

Liger-Belair, G. “How many bubbles in your glass of bubbly?” Journal of Physical Chemistry B 118, 3156-3163, 2014.

Liger-Belair, G.; Bourget, M.; Villaume, S.; Jeandet, P.; Pron, H.; Polidori, G. “On the losses of dissolved CO2 during champagne serving” Journal of Agricultural and Food Chemistry 58, 8768-8775, 2010.

The Applicant has sought to better understand the interest of bubbling and has identified two main areas. The bubbling offers a pleasant aspect which reinforces the interest of the consumer. The Applicant then sought to increase the duration of the bubbling so that a consumer leaving his glass to stand does not end up with a beverage that has exhausted its bubbling gas. The Applicant also had the idea of looking at the spatial distribution of bubbling and its effects on the beverage. It turns out that the bubbles load up with aromatic particles as they rise through the beverage. The bubbling therefore has an effect on the taste perceived by the consumer beyond the gradual reduction in the dissolved gas content. A complex interaction with the shape of the container is also glimpsed. The bubbling seems more durable with bubbles starting from an edge rather than the center. From another point of view, the Applicant realized that if the chemistry and physics of the nucleation sites had been the object of interesting studies, the geography of the nucleation sites had been neglected.

SUMMARY

There is proposed a sparkling beverage container, in particular a effervescent wine glass, comprising a barrier wall made of at least one structural material, the barrier wall defining an internal surface having a bottom portion between a bottom of the barrier wall and a region of maximum diameter and an edge portion located above the bottom portion, the barrier wall comprising, in the bottom portion, a plurality of open pores forming a pattern occupying an area of between 0.01 and 5%, preferably between 0.10 and 1%, of the area of the bottom portion and having an open cross shape. A convective mixing is obtained in the transverse plane and in the horizontal plane.

In one embodiment, the sparkling beverage container is made of glass,

In one embodiment, the area is comprised between 10 and 40% of the area of the bottom portion.

In one embodiment, the cross has straight-line segment branches.

In one embodiment, the cross has intersecting segments.

In one embodiment, the cross has disjoint segments at the center.

In one embodiment, the cross has a number of branches comprised between 3 and 10. Said branches can be contiguous or not contiguous.

In one embodiment, the cross has at least one discontinuity. Said at least one discontinuity can be oriented perpendicular to the direction of a segment or obliquely.

In one embodiment, the pattern has a plurality of point areas having said pores. The cross shape can consist of spots, rods, circles, squares, etc.

In one embodiment, the barrier wall forms a gob having a diameter at the mouth smaller than the diameter at mid-height.

In one embodiment, the barrier wall forms a gob having a height greater than the diameter at mid-height. Mixing by convection is greater for glasses with a high and narrow gob than for glasses with a low and wide gob. A flute-shaped glass generates greater mixing. The radius R of a bubble increases with the distance D travelled in the beverage with a relationship less than the square root, with k a constant: R<k (D)0.5. The upward rise speed of a bubble increases with the square of the radius R. The upward rise speed therefore increases with the distance D. Preferably, the height is greater than the maximum diameter, better still twice the maximum diameter.

For such a container, the radial distribution of the pattern generates central bubbles and parietal bubbles. The parietal bubbles reach the surface by being of dimension smaller than the dimension of the central bubbles.

In the case of a goblet, the gob forms the bulk of the container. In the case of a stemmed glass, the gob is supported by the stem.

In one embodiment, said cross has at least two branches extending, in developed length, over more than 90% of the maximum radius of the bottom portion.

In one embodiment, said cross has at least two branches extending, in projection in a plane normal to the axis of the gob, over more than 80% of the maximum radius of the bottom portion.

In one embodiment, said two branches are opposite if the number of branches is even.

In one embodiment, said two branches are disposed at least 120° from each other if the number of branches is odd.

In one embodiment, the cross is centered on an axis of symmetry of the container.

In one embodiment, the cross has branches with a width comprised between 0.1 and 5 mm, preferably between 0.25 and 0.80 mm.

In one embodiment, the cross has branches of equal lengths, equal widths, and a discontinuity in the center.

In one embodiment, the pattern consists of concavities having a depth comprised between 0.001 and 0.080 mm, preferentially between 0.001 and 0.040 mm, more preferentially between 0.001 and 0.010 mm.

In one embodiment, the concavities have a width comprised between 0.0005 and 0.002 mm.

In one embodiment, the concavities have a length comprised between 0.001 and 0.300 mm, preferably between 0.075 and 0.200 mm.

In one embodiment, the concavities have a length per surface unit comprised between 0.11 m-1 and 0.28 m-1.

In one embodiment, the concavities comprise perforations have a diameter comprised between 0.050 and 0.300 mm, preferably between 0.100 and 0.200 mm.

In one embodiment, the perforations have a diameter to depth ratio comprised between 2 and 4, preferably between 2.5 and 3.5.

In one embodiment, the perforations are formed by applying a dot laser beam. The points of application of the laser beam cause local cracking of the wall. Said cracks may originate from application points. Said cracks form concavities.

In one embodiment, the laser beam has a power comprised between 10 and 500 W, a frequency comprised between 1 and 20 kHz and a displacement speed comprised between 1 and 10 m/s, for example a power of 100 W, a frequency of 5 kHz and a speed of 5 m/s.

The container may further comprise a glass body. The transparency allows to visualize the appearance and the path of the bubbles from the nucleation site to the surface of the beverage.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features, details and advantages of the invention will appear upon reading the detailed description below, and the appended drawings, wherein:

FIG. 1 is a sectional view of a container according to one aspect of the invention,

FIG. 2 is a sectional view of a container according to one aspect of the invention,

FIG. 3 is a sectional view of a container according to one aspect of the invention,

FIG. 4 is a cross-sectional photo of a container according to one aspect of the invention,

FIG. 5 is a cross-sectional photo of a container according to one aspect of the invention,

FIG. 6 is a cross-sectional photo of a container according to one aspect of the invention,

The drawings and the description below contain, for the most portion, certain elements. They may therefore not only be used to better understand the present invention, but also contribute to its definition, if necessary.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In a food liquid, the carbon dioxide (CO₂) dissolved in the liquid phase is the carrier gas of the effervescence phenomenon. The frequency of emission of bubbles during a tasting, the magnification of the bubbles in the container and the number of bubbles liable to be formed are related to a certain number of physico-chemical parameters of the liquid phase and of the container in which tasting is performed.

When a gas is contacted with a liquid, a portion of this gas dissolves in the liquid. Various factors influence the solubility of gas in liquid, in particular temperature and pressure. At equilibrium, there is a proportionality between the concentration in the liquid phase of a chemical species i, denoted Ci, and its partial pressure in the gas phase Pi. Henry's law is written:

C _(i)=kH P _(i)  [Math 1]

The proportionality constant kH is called Henry's constant. It strongly depends on the gas and the liquid considered, as well as on the temperature.

Under normal atmospheric pressure P_(o)≈1 bar, taking into account the solubility of CO₂ in a beer at 4° C. which is worth kH≈2.6 g/L/bar, said beer is capable of dissolving approximately 2.6 g/L of CO₂.

When a chemical substance i is in equilibrium on either side of a gas/liquid interface, its concentration in the liquid meets Henry's law. The liquid is then said to be saturated with respect to this substance. In this case, saturation means balance.

When the concentration CL of a chemical substance i in a liquid is greater than predicted by Henry's law, the liquid is supersaturated with respect to that substance. To quantify this non-equilibrium situation, the supersaturation coefficient Si is defined as the relative excess of concentration in a liquid of a substance i with respect to the reference concentration, denoted CO (chosen as the equilibrium concentration of this substance under a partial pressure equal to the pressure in the liquid PL). The supersaturation coefficient Si is therefore defined in the following form:

S _(i)=(C _(i) −C ₀)/C ₀  [Math 2]

When a liquid is supersaturated with respect to a chemical substance, we have Si>0. The liquid evacuates a portion of its content in this chemical substance to return to a new state of equilibrium which meets Henry's law.

In tasting conditions, in a container, the pressure in the liquid is almost identical to the ambient pressure. Given the low height of the liquid, which does not exceed 10 to 12 cm, the effect of the hydrostatic overpressure which reigns at the bottom of the container is negligible compared to atmospheric pressure. At a temperature of 4° C., it is then possible to deduce the equilibrium concentration as being equal to:

C ₀ =K _(H) P _(L) ≈K _(H) P ₀≈2.6 g/L  [Math 3]

Beers do not all have the same dissolved CO₂ concentration. Some are lightly loaded at 3-4 g/L, while others are heavily loaded, up to 7-8 g/L. Their respective supersaturation coefficients with respect to dissolved CO2 will therefore not be the same. In the case of an average beer, loaded at about 5 g/L. Its supersaturation coefficient (at 4° C.) by applying the equation [Math 2]:

S _(CO2)=(C _(i) −C ₀)/C ₀≈(5−2.6)/2.6≈0.9  [Math 4]

For comparison (still at 4° C.), strongly sparkling waters (of the Badoit Rouge type) have supersaturation coefficients of around 1.3, while Champagne wines (still young) have much higher coefficients, of the order of 3.4. In general, the higher the supersaturation coefficient of a liquid loaded with dissolved CO₂, the more intense the resulting dissolved carbon dioxide escape kinetics will be in order to return to Henry's equilibrium. However, it has been observed that the supersaturation of a liquid in dissolved gas is not necessarily synonymous with the formation of bubbles and therefore effervescence.

Indeed, at beer supersaturation values, the formation of bubbles requires the presence of gas pockets in the medium, whose radius of curvature rc exceeds a value called critical value defined as follows:

rc=2γ/P _(o) S  [Math 5]

where γ is the surface tension of the liquid, Po is the ambient pressure and S is the supersaturation coefficient of the liquid phase in CO₂.

At normal atmospheric pressure of 1 bar and at 4° C., in the case of a beer whose surface tension is typically 45 mN/m and the supersaturation coefficient is around 0.9, the previous equation shows a critical radius of the order of 1 μm below which the formation of bubbles does not take place.

To cause CO₂ bubbles to appear and grow in an effervescent wine, the medium contains therein gas microbubbles whose radii are greater than a critical radius. This is referred to as non-classical heterogeneous nucleation (as opposed to the nucleations called classical nucleations which concern the spontaneous formation, ex nihilo, of bubbles in a highly supersaturated liquid). Classic nucleations require very high dissolved gas supersaturation coefficients (>100), which are incompatible with sparkling beverages.

The question then arises of the origin of the gas germs which are the catalysts of the effervescence in a container.

The critical nucleation radius takes into account the concentration of dissolved CO₂ in the beverage, cf. equations [Math 4] and [Math 5]. However, after serving, said concentration is no longer the same as the initial concentration. Serving is a critical step. Indeed, the pouring into the container generates significant turbulence which accelerates the escape of the dissolved carbon dioxide. The colder the beverage, the more dissolved carbon dioxide is kept dissolved at the time of serving. Indeed, the beverage is particularly viscous as it is cold. However, the diffusion rate of dissolved CO₂ out of the beverage is all the more rapid as the viscosity is low. In addition, the turbulence of pouring is particularly effectively reduced when the beverage is viscous. Consequently, the colder the beverage is served, the better the conservation of dissolved carbon dioxide during service.

For effervescent wine, the critical radius is influenced by several factors: type of wine, sugar level, composition, etc.

Moreover, it has been established that the flow of bubbles, that is to say the number of bubbles per second, is proportional to the square of the temperature, to the concentration of CO₂ dissolved in the liquid, and inversely proportional to the dynamic viscosity (in kg/m/s).

By looking more closely at the bubbling phenomenon of effervescent wines, the Applicant has carried out tests by implementing effervescent wine glasses whose bottom is made rough by laser shots on the uncoated glass wall. The glass after a normal finish giving it a smooth surface is treated with a laser beam generating controlled impacts in the bottom wall from the internal surface.

Unlike beer glasses whose bottom is generally flat, effervescent wine glasses, of the flute or goblet type, have bottoms of variable height, in particular inverted ogive, parabolic, brace, etc. of various curvatures.

These tests have shown the interest of a radially distributed bubbling, in particular by the mixing caused by the distributed bubbling by mass convection.

A container 1 is shown in the figures. The container 1 here is in the shape of a stemmed glass. The method described below applies to most containers for sparkling beverages for which the control of effervescence is of interest.

The container 1 comprises, here, a foot 2 and a gob 3. The gob 3 comprises a bottom 4 and an upper wall 5 of substantially cylindrical or frustoconical shape. The container 1 is, here, axisymmetric. In the example described here, the bottom 4 and the gob 3 form a one-piece body. The gob 3 has an inner bottom surface and an inner edge surface. The gob 3 is watertight. The internal surfaces are intended to be in contact with the beverage when using the container 1.

The container 1 can be obtained by manufacturing techniques known as such, for example by pressing, blowing and/or by centrifugation. At the output of such manufacturing techniques, the interior of the container 1 is substantially smooth and uniform. The container 1 is marketable as is.

The smooth container 1 is treated to form blind perforations 6 on the upper surface of the bottom 4 located on the side of the upper wall 5, that is to say the internal bottom surface.

The perforations 6 are applied to the bottom of the gob 3 in a cruciform pattern. The pattern here is a cross with 4 branches of equal length, equal width and circumferentially regularly distributed. The material of the container 1, here a glass, is the object of laser shots forming the perforations 6 and thus determining the pattern.

The pattern has a length slightly less than the maximum inner diameter of the gob 3, for example greater than 90% of the maximum inner diameter of the gob 3.

The cross can have diametrical branches of length comprised between 4 and 6 cm. The cross here has an open shape. The crosses comprising closed shapes, lobed crosses, Celtic crosses, are less interesting. Indeed, a circular pattern would have a length of PI times the diameter while the square cross has a length of 2 times the diameter, hence faster manufacturing and slow and persistent bubbling while offering a satisfactory appearance and efficient mixing.

The branches of the cross can have a width of a few tenths of a millimeter to a few millimeters, for example between 0.025 and 0.080 mm, more generally comprised between 0.1 and 5 mm. A branch of the cross can be formed of perforations 6 disposed randomly within the pattern or disposed in an ordered manner, for example in one or more rows.

In relation to the area of the bottom portion, the pattern occupies an area comprised between 0.01 and 5%, preferably between 0.10 and 1%. Such a surface allows prolonged bubbling of at least 10 minutes.

The cross can have branches of constant or variable width.

The cross can have branches in an even number, 4, 6, 8 or 10, passing through the center or interrupted near the center.

The cross can have branches in an odd number, 3, 5, 7 or 9, passing through the center or interrupted near the center.

The interruption in the center allows a more homogeneous distribution of the perforations 6 on the surface of the bottom portion.

In FIG. 1 , a stemmed glass has a cruciform design. The gob 3 has a maximum diameter comprised between 40 and 45% of its internal height. The gob 3 has an internal height comprised between 180 and 200% of the maximum diameter.

In FIG. 2 , a stemmed glass has a cruciform design. The gob 3 has a maximum diameter comprised between 45 and 50% of its internal height. The gob 3 has an internal height comprised between 170 and 180% of the maximum diameter.

In FIG. 3 , a stemmed glass has a cruciform design. The gob 3 has a maximum diameter comprised between 70 and 80% of its internal height. The gob 3 has an internal height comprised between 110 and 130% of the maximum diameter.

FIG. 4 shows the comparison between two flute-shaped champagne glasses, one known in smooth glass on the left and the other, according to the invention, filled with the same champagne under the same operating conditions of pressure, temperature, luminosity, etc. Said other glass is provided with perforations 6 close to the center and therefore to the bottom of the glass. The movement of the wine generated by the bubbling is visible and the rotary stirring movement is significant.

FIG. 5 shows a glass filled with champagne, according to the invention, with a cruciform pattern as in FIGS. 1 to 3 . A curtain of bubbles is visible and causes significant mixing with slow and stable degassing.

FIG. 6 shows a glass filled with champagne, according to the invention, with a cruciform pattern as in FIGS. 1 to 3 . After 10 minutes of bubbling the glass held still, a curtain of bubbles remains visible and maintains stirring. 

1. A sparkling beverage container (1), in particular a glass, comprising a barrier wall made of at least one structural material, the barrier wall defining an internal surface having a bottom portion between a bottom (4) of the barrier wall and a region of maximum diameter and an edge portion located above the bottom portion, the barrier wall comprising, in the bottom portion, a plurality of open pores (6) forming a pattern occupying an area of between 0.01 and 5% of the area of the bottom portion and having an open cross shape.
 2. The sparkling beverage container according to claim 1, wherein the cross has straight-line segment branches.
 3. The sparkling beverage container according to claim 1, wherein the cross has a number of branches comprised between 3 and 10, said branches are contiguous or not contiguous.
 4. The sparkling beverage container according to claim 1, wherein the cross has at least one discontinuity.
 5. The sparkling beverage container according to claim 1, wherein the pattern has a plurality of point areas having said pores.
 6. The sparkling beverage container according to claim 1, wherein the barrier wall forms a gob (3) having a diameter at the mouth smaller than a diameter at mid-height and a height greater than a diameter at mid-height.
 7. The sparkling beverage container according to claim 1, wherein said cross has at least two branches extending, in developed length, over more than 90% of the maximum radius of the bottom portion, said two branches being opposite if the number of branches is even and disposed at least 120° from each other if the number of branches is odd.
 8. The sparkling beverage container according to claim 1, wherein the cross is centered on an axis of symmetry of the container.
 9. The sparkling beverage container according to claim 1, wherein the cross has branches with a width comprised between 0.1 and 5 mm.
 10. The sparkling beverage container according to claim 1, wherein the cross has branches of equal lengths, equal widths, and a discontinuity in the center. 